The present invention relates to an oil-cooled air compressor.
In the oil-cooled air compressor, there is a provability of that when a temperature of the air discharged from the compressor decreases to not more than a critical temperature in occurrence of condensed water, a water component of the gas is condensed to the water so that a rust is formed in the compressor. Therefore, a lubricant temperature control is important, and in the prior art, a type of the lubricant temperature control in which a flow rate of the lubricant circulating through a heat exchanger is adjusted in accordance with the lubricant temperature measured by a lubricant flow rate adjuster in a lubricant passage is mainly used.
On the other hand, in recent years, an inverter control of cooling fan for cooling the lubricant has been improved for energy-saving and decrease in noise of the cooling fan. This is a type in which a flow rate of a cooling medium supplied to the heat exchanger is adjusted in accordance with the lubricant temperature measured by a temperature sensor or the like, for example, in JP-A-6-213186, a flow rate of cooling air supplied to the heat exchanger for the lubricant is adjusted in accordance with the lubricant temperature measured by the temperature sensor arranged at the lubricant passage to keep the temperature of the lubricant constant so that the condensed water is prevented from being formed in the compressor.